Description of problem:
When I choose to log out from Gnome and expect to get the confirmation
requester (the one with choices to reboot or shutdown the computer), gnome
instead seems to crash X entirely (which in my case makes init respawn X
and I'm back to the gdm greeter).

Version-Release number of selected component (if applicable):
gnome-session-2.4.0-1
I'm running latest (i386 precompiled) Rawhide versions of all XFree86 and
gnome packages.

How reproducible:
100%

Steps to Reproduce:
1. Choose to log out either from main menu or from a log out button on my panel
    
Actual results:
A confirmation requester with choices to logout/reboot/poweroff

Expected results:
X crashes

Additional info:
The really strange with this is that it only happens if I have a second
screen configured in XF86Config and they screens are not in xinerama mode
(that is, I have one monitor at :0.0 and one at :0.1). I fail to see the
connection here, but I've tried quite some times and this is the case. Maybe the
fancy logout effect can't handle multiple screens?

I get the following in my .xsession-errors:

The program 'gnome-session' received an X Window System error.
This probably reflects a bug in the program.
The error was 'BadMatch (invalid parameter attributes)'.
  (Details: serial 1471 error_code 8 request_code 1 minor_code 0)
  (Note to programmers: normally, X errors are reported asynchronously;
   that is, you will receive the error a while after causing it.
   To debug your program, run it with the --sync command line
   option to change this behavior. You can then get a meaningful
   backtrace from your debugger if you break on the gdk_x_error() function.)